Yes, greys is a Scrabble word!

Verb

1. Make grey

2. Turn grey

Noun

1. United States writer of western adventure novels (1875-1939)

2. Queen of England for nine days in 1553; she was quickly replaced by Mary Tudor and beheaded for treason (1537-1554)

3. Englishman who as Prime Minister implemented social reforms including the abolition of slavery throughout the British Empire (1764-1845)

4. Any organization or party whose uniforms or badges are grey

5. A neutral achromatic color midway between white and black

6. Clothing that is a grey color

7. Horse of a light gray or whitish color